OpenSceneGraph/include/osgShadow/OccluderGeometry
2007-04-06 15:36:13 +00:00

260 lines
9.0 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* OpenSceneGraph Public License for more details.
*/
#ifndef OSGSHADOW_OCCLUDERGEOMETRY
#define OSGSHADOW_OCCLUDERGEOMETRY 1
#include <osg/Drawable>
#include <osg/Array>
#include <osg/PrimitiveSet>
#include <osg/Polytope>
#include <osgShadow/Export>
namespace osgShadow {
class ShadowVolumeGeometry;
/** OccluderGeometry provides a sepecialised geometry representation of objects in scene that occlude light and therefore cast shadows.
* OccluderGeometry supports the computation of silhouette edges and shadow volume geometries, as well as use as geometry that one can rendering
* into a shadow map or end caps for the ZP+ algorithm. OccluderGeometry may be of the same resolution as an underlying geometry that it
* represents, or can be of lower resolution and combine manager seperate geometries together into a single shadow casting object.
* OccluderGeometry may be attached as UserData to Nodes or to Drawables. */
class OSGSHADOW_EXPORT OccluderGeometry : public osg::Drawable
{
public :
OccluderGeometry();
OccluderGeometry(const OccluderGeometry& oc, const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
virtual Object* cloneType() const { return new OccluderGeometry(); }
virtual Object* clone(const osg::CopyOp& copyop) const { return new OccluderGeometry(*this,copyop); }
virtual bool isSameKindAs(const osg::Object* obj) const { return dynamic_cast<const OccluderGeometry*>(obj)!=NULL; }
virtual const char* libraryName() const { return "osgShadow"; }
virtual const char* className() const { return "OccluderGeometry"; }
/** Compute an occluder geometry containing all the geometry in specified subgraph.*/
void computeOccluderGeometry(osg::Node* subgraph, osg::Matrix* matrix=0, float sampleRatio=1.0f);
/** Compute an occluder geometry containing the geometry in specified drawable.*/
void computeOccluderGeometry(osg::Drawable* drawable, osg::Matrix* matrix=0, float sampleRatio=1.0f);
/** Compute ShadowVolumeGeometry. */
void computeShadowVolumeGeometry(const osg::Vec4& lightpos, ShadowVolumeGeometry& svg) const;
/** Set the bounding polytope of the OccluderGeometry.*/
void setBoundingPolytope(const osg::Polytope& polytope) { _boundingPolytope = polytope; }
/** Get the bounding polytope of the OccluderGeometry.*/
osg::Polytope& getBoundingPolytope() { return _boundingPolytope; }
/** Get the const bounding polytope of the OccluderGeometry.*/
const osg::Polytope& getBoundingPolytope() const { return _boundingPolytope; }
/** Render the occluder geometry. */
virtual void drawImplementation(osg::RenderInfo& renderInfo) const;
/** Compute the bounding box around occluder geometry.*/
virtual osg::BoundingBox computeBound() const;
typedef std::vector<osg::Vec3> Vec3List;
typedef std::vector<GLuint> UIntList;
public:
void processGeometry(osg::Drawable* drawable, osg::Matrix* matrix=0, float sampleRatio=1.0f);
protected :
virtual ~OccluderGeometry() {}
struct Edge
{
Edge():
_p1(0),
_p2(0),
_t1(-1),
_t2(-1) {}
Edge(unsigned int p1, unsigned int p2):
_p1(p1),
_p2(p2),
_t1(-1),
_t2(-1)
{
if (p1>p2)
{
// swap ordering so p1 is less than or equal to p2
_p1 = p2;
_p2 = p1;
}
}
inline bool operator < (const Edge& rhs) const
{
if (_p1 < rhs._p1) return true;
if (_p1 > rhs._p1) return false;
return (_p2 < rhs._p2);
}
bool addTriangle(unsigned int tri) const
{
if (_t1<0)
{
_t1 = tri;
return true;
}
else if (_t2<0)
{
_t2 = tri;
return true;
}
// argg more than two triangles assigned
return false;
}
bool boundaryEdge() const { return _t2<0; }
unsigned int _p1;
unsigned int _p2;
mutable int _t1;
mutable int _t2;
mutable osg::Vec3 _normal;
};
typedef std::vector<Edge> EdgeList;
inline bool isLightPointSilhouetteEdge(const osg::Vec3& lightpos, const Edge& edge) const
{
if (edge.boundaryEdge()) return true;
float offset = 0.0f;
osg::Vec3 delta(lightpos-_vertices[edge._p1]);
delta.normalize();
float n1 = delta * _triangleNormals[edge._t1] + offset;
float n2 = delta * _triangleNormals[edge._t2] + offset;
float angle_offset = 0.0f;
n1 = cos(acosf(n1) + angle_offset);
n2 = cos(acosf(n2) + angle_offset);
if (n1==0.0f && n2==0.0f) return false;
return n1*n2 <= 0.0f;
}
inline bool isLightDirectionSilhouetteEdge(const osg::Vec3& lightdirection, const Edge& edge) const
{
if (edge.boundaryEdge()) return true;
float offset = 0.0f;
float n1 = lightdirection * _triangleNormals[edge._t1] + offset;
float n2 = lightdirection * _triangleNormals[edge._t2] + offset;
float angle_offset = 0.0f;
n1 = cos(acosf(n1) + angle_offset);
n2 = cos(acosf(n2) + angle_offset);
if (n1==0.0f && n2==0.0f) return false;
return n1*n2 <= 0.0f;
}
void setUpInternalStructures();
void removeDuplicateVertices();
void removeNullTriangles();
void computeNormals();
void buildEdgeMaps();
void computeLightDirectionSlihouetteEdges(const osg::Vec3& lightdirection, UIntList& silhouetteIndices) const;
void computeLightPositionSlihouetteEdges(const osg::Vec3& lightpos, UIntList& silhouetteIndices) const;
osg::Polytope _boundingPolytope;
Vec3List _vertices;
Vec3List _normals;
Vec3List _triangleNormals;
UIntList _triangleIndices;
EdgeList _edges;
};
class OSGSHADOW_EXPORT ShadowVolumeGeometry : public osg::Drawable
{
public :
ShadowVolumeGeometry();
ShadowVolumeGeometry(const ShadowVolumeGeometry& oc, const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
virtual Object* cloneType() const { return new ShadowVolumeGeometry(); }
virtual Object* clone(const osg::CopyOp& copyop) const { return new ShadowVolumeGeometry(*this,copyop); }
virtual bool isSameKindAs(const osg::Object* obj) const { return dynamic_cast<const ShadowVolumeGeometry*>(obj)!=NULL; }
virtual const char* libraryName() const { return "osgShadow"; }
virtual const char* className() const { return "ShadowVolumeGeometry"; }
enum DrawMode
{
GEOMETRY,
STENCIL_TWO_PASS,
STENCIL_TWO_SIDED
};
void setDrawMode(DrawMode mode) { _drawMode = mode; }
DrawMode getDrawMode() const { return _drawMode; }
typedef std::vector<osg::Vec3> Vec3List;
typedef std::vector<GLuint> UIntList;
void setVertices(const Vec3List& vertices) { _vertices = vertices; }
Vec3List& getVertices() { return _vertices; }
const Vec3List& getVertices() const { return _vertices; }
void setNormals(const Vec3List& normals) { _normals = normals; }
Vec3List& getNormals() { return _normals; }
const Vec3List& getNormals() const { return _normals; }
/** Render the occluder geometry. */
virtual void drawImplementation(osg::RenderInfo& renderInfo) const;
/** Compute the bounding box around occluder geometry.*/
virtual osg::BoundingBox computeBound() const;
public:
protected :
virtual ~ShadowVolumeGeometry() {}
DrawMode _drawMode;
Vec3List _vertices;
Vec3List _normals;
UIntList _indices;
};
}
#endif